From DE 695 35 077 T2, a control system for a powder coating system is known. There, a communication network is provided, which connects control components of the powder coating system with powder sprayers, which spray powder coating materials on parts that are to be coated. The disadvantage there is that there is no monitoring of the pressure of the powder to be applied on the powder sprayers, but rather, the pressure is merely measured and adjusted, at a relatively far distance from the powder sprayers. A pressure fluctuation on the powder sprayers is, therefore, recognized only late and any application errors produced in this way are compensated for only poorly. In addition, in such a system, leakages in the supply lines or a clogging are not detected; an insufficient coating result is attained due to a decrease or increase in pressure. The long lines before the adjusting and measuring elements to the sprayer lead to inaccurate and delayed regulations and adjustments as a result of the relatively high volumes.
U.S. Pat. No. 5,443,642 concerns a system for electrostatic color coating, wherein the pressure there is measured via pressure sensors and the air humidity, via humidity sensors, which, however, are not directly located on a color sprayer. Rather, permanently installed spray heads are used there, with the workpiece moving past them.
Another electrostatic sprayer can be deduced from DE 34 02 945 C2, which has on it a voltage display with a display field pointing backwards. Dependent on the voltage on the sprayer, a light-emitting diode shines, so that changes in the voltage can be quickly detected.
Since, in contrast to powder coating systems with color sprayers and lacquer spray guns for liquid colors, the quality of the color application is decisively dependent on the atomization and thus on the pressure directly applied on the sprayer nozzle, the known powder coating system does not offer a sufficiently good solution for fluid-operated color sprayers. In particular, it is not possible there to measure directly the pressure on the sprayers and thus to promptly regulate them.
With known color sprayers or lacquer spray guns, in particular, for liquid media, such as paint, digital pressure measuring devices are used in the sprayer, wherein the tracking of the pressure on the color sprayer takes place either via manually adjustable throttles or via pressure regulators, which are located at a distance from the color sprayer. In order to change the pressure applied on the color sprayer, the pressure must be readjusted, via the throttle or the pressure regulator, until the desired pressure on the color sprayer is attained. This is susceptible to error, in particular if the environmental conditions change, for example, the pressure hose to the color sprayer is bent or has constrictions; the position of the color sprayer changes during the application of the color; other consumers are connected or disconnected, etc. The application result is influenced negatively by the pressure changes which thereby occur.
U.S. Pat. No. 5,381,962 discloses an example of such a color application system in the form of a sprayer and the transmitter located therein, for the wireless data transfer, with a receiver of a pump module. There, adjustments on the color sprayer can be undertaken with the aid of switches on the sprayer; these can then be transferred to the pump module. Thus, the pump module can be operated from the color sprayer, wherein this must always take place manually—that is, in a relatively slow and inaccurate manner.
Also, U.S. Pat. No. 4,614,300, which concerns an automatic color application system, merely discloses that a control and supply of mechanically moveable sprayers takes place. Data on the sprayers are neither detected nor sent back from there to the control of the color application system.